The container for a sample such as blood is sealed with a plug made of rubber or the like to prevent degradation and leakage of the sample. Some automatic analyzers using such a sample container are compatible with closed tube sampling (CTS) by which a sample can be dispensed and analyzed without having to unplug the sample container. The CTS-compatible automatic analyzer includes a dispensing mechanism having a nozzle with a sharp tip for piercing a rubber plug with a thickness of about 6 mm (hereinafter, also called CTS nozzle) to let the CTS nozzle pierce the plug to aspirate the sample in the container. The general CTS nozzle has the tip sharped by obliquely cutting one surface of the tip of a metal tube with a hollow as described in PTL 1.
In addition, some CTS nozzles have a needle-like blade at the tip of the hollow metallic tube and an opening for aspirating the sample on the side surface of the nozzle as described in PTLs 2 and 3.
Meanwhile, there is a method by which a paracentesis needle separately from a nozzle is provided to open the rubber plug and pass the nozzle through the opening in the rubber plug opened by the paracentesis needle to aspirate the sample as described in PTL 4.